The present invention relates to a strobe circuit, to which another electronic circuit or electronic element is added, and a printed circuit board for strobe, which comprises two circuit boards, and also relates to a lens-fitted film unit and a camera, which incorporates the abovementioned strobe circuit or printed-circuit board for strobe.
Conventionally, quite a few lens-fitted film units, incorporated with a strobe, have been put in the market. FIG. 1 shows an example of the strobe circuit diagram employed for such lens-fitted film units.
In FIG. 1, when main switches S1, S2 are turned ON by an external operation, the electronic current, fed from battery B, flows into transistor TR through resistor R1 to start the oscillation, by which the high-voltage of 300-350 volts is induced at the secondary winding of oscillation transformer T. The induced electronic current from the secondary winding is rectified by diode D, and the rectified electronic current flows into main-capacitor CM and trigger-capacitor CT, serially connected with resistor R1, to charge them. When main-capacitor CM is charged to a predetermined voltage, light-emitting diode DL, serially connected with resistor R2, emits light.
When capturing image, trigger-switch ST turns ON in conjunction with the opening operation of shutter blinds. Then, the closed circuit, including trigger-capacitor CT, trigger-switch ST, the primary winding of trigger-transformer TC and main switches S1, S2, is formed to discharge the electronic charge stored in trigger-capacitor CT. As a result, the further high-voltage is induced in the secondary winding of trigger-transformer TC, and the induced high-voltage is applied to the trigger-electrode of xenon tube Xe, in which electrons, isolated from the cathode, impinge with ionized xenon atoms to excite the xenon atoms. Thus, xenon tube Xe emits the strobe light associating with the discharging action of main-capacitor CM.
Since it is a primary subject for the lens-fitted film unit to reduce its price as low as possible, it is difficult to equip various kinds of image capturing mechanisms in it. Nevertheless, consumers desire that more image capturing mechanisms are incorporated in the lens-fitted film unit, in order to enjoy the image capturing with better photographic images.
Although quite a few lens-fitted film units, incorporated with a strobe circuit, have been put in the market as aforementioned, the strobe circuit is utilized only for activating the strobe lighting in such lens-fitted film units, as a matter of course. The parts, included in the strobe circuit, however, are relatively expensive, and the battery and the main-capacitor require large spaces. Therefore, it has been quite wasteful for lens-fitted film units to limit the purpose of the strobe circuit within the strobe lighting.
To utilize the strobe circuit more efficiently, it may be possible to incorporate new electronic element and/or electronic circuit, having a certain added value, in the strobe circuit. Such new electronic element or electronic circuit, however, usually requires a separate power source, which extraordinarily raises the total cost of the apparatus concerned. This problem is specifically serious for the strobe device of the lens-fitted film unit, the price of which should be reduced as low as possible.
To overcome the abovementioned drawbacks in conventional strobe devices, it is the first object of the present invention to provide a strobe device, which makes it possible to equip a new function in the strobe device by adding a little electronic circuit or some electronic parts to the fundamental circuit for strobe lighting.
Further, sometimes, it is difficult to mount an added circuit, having a new photographic function, on the small sized printed circuit board, which already mounts parts for the fundamental circuit for strobe lighting. To solve this problem, the second object of the present invention is to provide a combination of two printed circuit boards, strictly coupled to each other, which is disposed in a vacant space of a lens-fitted film unit or a camera.
Accordingly, to overcome the cited shortcomings, the abovementioned objects of the present invention can be attained by a strobe device, a lens-fitted film unit and a camera described as follow.
(1) A strobe device, comprising: a strobe light-emitting tube to emit a strobe light; a main-capacitor coupled in parallel to the strobe light-emitting tube, so as to supply a luminous energy to the strobe light-emitting tube; a trigger-transformer to apply a trigger-voltage to a trigger-electrode of the strobe light-emitting tube; a trigger-section to activate a light-emitting action of the strobe light-emitting tube; a trigger-capacitor, coupled to the main-capacitor with a resistor, to store an electronic charge, which is discharged to the trigger-transformer when the trigger-section turns ON; and an operating section driven by a part of an electronic charge, stored in the main-capacitor, flowing through the resistor when the trigger-section turns ON to activate the light-emitting action of the strobe light-emitting tube.
(2) The strobe device of item 1, wherein a closed circuit, serially connecting the trigger-capacitor, the trigger-section and a primary winding of the trigger-transformer, is formed when the trigger-section turns ON, and simultaneously, another closed circuit, serially connecting the main-capacitor, the operating section, the resistor, the trigger-section and the primary winding of the trigger-transformer, is formed.
(3) The strobe device of item 1, wherein the operating section is a constant-voltage generating element.
(4) The strobe device of item 3, wherein the constant-voltage generating element is a zener diode.
(5) The strobe device of item 4, wherein an anode of the zener diode is coupled to a negative pole of the main-capacitor.
(6) The strobe device of item 3, wherein an added circuit, which is driven by a voltage-source generated by the constant-voltage generating element, is coupled in parallel to the constant-voltage generating element.
(7) The strobe device of item 6, wherein the added circuit is a light-intensity regulating circuit, which controls an amount of the strobe light emitted from the strobe device, in response to an amount of the strobe light reflected from a subject.
(8) The strobe device of item 7, further comprising: a first printed circuit board on which electronic parts, constituting a fundamental circuit for a strobe lighting, including at least a voltage-boosting circuit, a charging circuit and a illumination circuit, are mounted; and a second printed circuit board on which electronic parts, constituting an electronic circuit other than the fundamental circuit, are mounted, wherein the first printed circuit board and the second printed circuit board are coupled to each other by means of a conductive member having an electronic conductivity, and the light-intensity regulating circuit is equipped on the second printed circuit board.
(9) The strobe device of item 8, wherein the first printed circuit board and the second printed circuit board are coupled to each other by means of at least the two conductive members.
(10) The strobe device of item 1, wherein the operating section is a light-emitting diode.
(11) The strobe device of item 10, wherein a cathode of the light-emitting diode is coupled to a negative pole of the main-capacitor.
(12) A lens-fitted film unit equipped with a strobe device, comprising: a main-body; a photographic lens; a shutter; and a photographic film loaded in the main-body, wherein the strobe device comprises, a strobe light-emitting tube to emit a strobe light, a main-capacitor coupled in parallel to the strobe light-emitting tube, so as to supply a luminous energy to the strobe light-emitting tube, a trigger-transformer to apply a trigger-voltage to a trigger-electrode of the strobe light-emitting tube, a trigger-section to activate a light-emitting action of the strobe light-emitting tube, a trigger-capacitor, coupled to the main-capacitor with a resistor, to store an electronic charge, which is discharged to the trigger-transformer when the trigger-section turns ON, and an operating section driven by a part of an electronic charge, stored in the main-capacitor, flowing through the resistor when the trigger-section turns ON to activate the light-emitting action of the strobe light-emitting tube.
(13) The lens-fitted film unit of item 12, wherein the trigger-section turns ON in conjunction with a opening action of the shutter.
(14) The lens-fitted film unit of item 12, wherein the operating section is a light-emitting diode, and a print type of a captured image is selectable by a photographer in the lens-fitted film unit, and the light-emitting diode exposes a mark, corresponding to the print type selected by the photographer, on an unexposed area, outside a photographic image area, of the photographic film.
(15) The lens-fitted film unit of item 12, further comprising: a power source to supply an electronic power to the strobe device, the power source is a battery of 1-2 volt.
(16) A camera equipped with a strobe device, comprising: a photographic lens; and a shutter, wherein the strobe device comprises, a strobe light-emitting tube to emit a strobe light, a main-capacitor coupled in parallel to the strobe light-emitting tube, so as to supply a luminous energy to the strobe light-emitting tube, a trigger-transformer to apply a trigger-voltage to a trigger-electrode of the strobe light-emitting tube, a trigger-section to activate a light-emitting action of the strobe light-emitting tube, a trigger-capacitor, coupled to the main-capacitor with a resistor, to store an electronic charge, which is discharged to the trigger-transformer when the trigger-section turns ON, and an operating section driven by a part of an electronic charge, stored in the main-capacitor, flowing through the resistor when the trigger-section turns ON to activate the light-emitting action of the strobe light-emitting tube.
(17) The camera of item 16, wherein the trigger-section turns ON in conjunction with a opening action of the shutter.
(18) The camera of item 16, wherein the operating section is a light-emitting diode, and a print type of a captured image is selectable by a photographer in the camera, and the light-emitting diode exposes a mark outside a photographic image area of an unexposed film, corresponding to the print type selected by the photographer.
Further, to overcome the abovementioned problems, other strobe devices, lens-fitted film units and cameras, embodied in the present invention, will be described as follow:
(19) A strobe circuit, characterized in that the strobe circuit is provided with a xenon tube to emit a strobe light; a main-capacitor coupled in parallel to the xenon tube,-so as to supply a high-voltage energy to the xenon tube; a trigger-transformer to apply a high-voltage to a trigger-electrode of the xenon tube; a trigger-capacitor, coupled to the main-capacitor with a resistor so as to charge an electronic charge, which discharges the electronic charge to the trigger-transformer when the trigger-means turns ON; and an operating means driven by a part of an electronic charge of the main-capacitor, flowing through the resistor when the xenon tube emits light by turning the trigger-means ON.
(20) A strobe circuit, characterized in that the strobe circuit is provided with a xenon tube to emit a strobe light; a main-capacitor coupled in parallel to the xenon tube, so as to supply a high-voltage energy to the xenon tube; a trigger-switch, which turns ON in conjunction with an opening action of a shutter blind; a trigger-transformer to apply a high-voltage to a trigger-electrode of the xenon tube; a trigger-capacitor, coupled to the main-capacitor with a resistor so as to charge an electronic charge, which discharges the electronic charge to the trigger-transformer when the trigger-means turns ON; and an operating means, wherein a closed circuit, serially connecting the trigger-capacitor, the trigger-switch and a primary winding of the trigger-transformer, is formed when the trigger-section turns ON, and simultaneously, another closed circuit, serially connecting the main-capacitor, the operating means, the resistor, the trigger-switch and the primary winding of the trigger-transformer, is formed, in order to drive the operating means by flowing a part of the electronic charge of the main-capacitor into the operating means.
(21) The strobe circuit of item 19 or 20, characterized in that the operating-means is a light-emitting diode, a cathode of which is coupled to a negative pole of the main-capacitor.
(22) A lens-fitted film unit, characterized in that the lens-fitted film unit is provided with the strobe device described in item 21, and the light-emitting diode emits light to conduct an exposing action at outside of an image area of an unexposed film, corresponding to a print type selected by a photographer.
(23) A camera, characterized in that the camera is provided with the strobe device described in item 21, and the light-emitting diode emits light to conduct an exposing action at outside of an image area of an unexposed film, corresponding to a print type selected by a photographer.
(24) The strobe circuit of item 19 or 20, characterized in that the operating means is a zener diode, an anode of which is coupled to a negative pole of the main-capacitor.
(25) The strobe circuit of item 24, characterized in that an added circuit, which is driven by a voltage generated by the zener diode, is coupled in parallel to the zener diode.
(26) The strobe circuit of item 25, characterized in that the added circuit is a light-intensity regulating circuit, which controls an amount of the strobe light emitted from the strobe device, in response to an amount of the strobe light reflected from a subject.
(27) A lens-fitted film unit, characterized in that the lens-fitted film unit is provided with the strobe circuit described in item 26.
(28) A camera, characterized in that the camera is provided with the strobe circuit described in item 26.
(29) A printed circuit board for strobe lighting, characterized in that the printed circuit board comprises a first printed circuit board on which electronic parts, constituting a fundamental circuit for a strobe lighting, including at least a voltage-boosting circuit, a charging circuit and a illumination circuit, are mounted; and a second printed circuit board on which electronic parts, constituting an electronic circuit other than the fundamental circuit, are mounted, wherein the first printed circuit board and the second printed circuit board are coupled to each other by means of at least two conductive members having an electronic conductivity.
(30) The printed circuit board, for strobe lighting, of item 29, characterized in that the light-emitting diode, in the strobe circuit described in item 21, is mounted on the second printed circuit board.
(31) The printed circuit board, for strobe lighting, of item 29, characterized in that the light-intensity regulating circuit, in the strobe circuit described in item 26, is equipped on the second printed circuit board.
(32) A lens-fitted film unit, characterized in that the printed circuit board, for strobe lighting, of item 29, is equipped in the lens-fitted film unit.
(33) A camera, characterized in that the printed circuit board, for strobe lighting, of item 29, is equipped in the camera.